Twelve hours after the front windows and main door of his four-year-old son's school were blown out by a bomb, Khalid Abdelrahim peered past the police barrier to study the damage.

"The people in Holland are good, but the politics here is not," said Mr Abdelrahim, who fled from Iraq to the Netherlands a decade ago. "Now I will have to try to find a new school for my son."

In Eindhoven yesterday few doubted that the attack on an Islamic primary school in the early hours of Monday was an act of retribution after last week's murder of Theo van Gogh, a Dutch film-maker who had criticised abuses of women in Islamic marriages.

The bombers struck the Tariq Ziyad Ibnoe school at around 3.30am local time. It was not an isolated incident; in recent days there have been arson attacks against mosques in Huizen, Breda, Rotterdam and Utrecht. Posters insulting Islam that showed pictures of pigs' heads were plastered on a mosque in Rotterdam, while an immigrants' centre in Amsterdam was daubed with red paint.

Yesterday in racially mixed, middle-class Frankrijkstraat, the school's lawn was covered with glass shards as children's paintings fluttered in the smashed windows.

No one was injured but the blast, which local Muslims say is the third incident in a year, seemed designed to send a message. The school is one of the first Islamic schools in the Netherlands and many fear that this is just the start of attacks against the Muslim community.

At the local mosque, one worshipper, who said he came from Morocco and gave his name as Mimoun, describes the growing unease of his community. "We are not safe now," he said. "If they make a bomb and put that in an Islamic school, maybe the next target will be the Islamic centre and the mosque. This was a reaction after [the murder of] Van Gogh. But why must all Muslims pay the price?"

In 2002 the Netherlands was shocked by the assassination of the maverick anti-immigration campaigner Pim Fortuyn, who was murdered in the car park of a television network. Last week a similar fate befell Mr van Gogh, a descendant of the 19th-century artist, who had made a name for himself as an outspoken commentator on social issues such as immigration.

Although neither a politician nor a conventional right-winger, Mr van Gogh was an enemy of political correctness. The action that seems to have sealed his fate was the making of a film with Ayaan Hirsi Ali, a Somali-born Dutch MP who renounced Islam. Screened in August, the fictional work, called Submission, condemned the religion's treatment of women, and outraged Muslim groups.

As he made his way to work, Mr van Gogh was shot, then had his throat slashed. His killer left a note pinned to his chest with the knife used to attack him.

Police arrested a 26-year-old man of Dutch and Moroccan nationality, who is suspected of having links with extremist Islamic groups. Five others were detained after subsequent raids.

While the murder of Mr van Gogh has received condemnation from all sides, there is less unanimity about who is to blame for the climate of fear.

Reacting to Mr Fortuyn's success and to his campaign slogan, "the Netherlands is full", the centre-right coalition government has put immigration near the top of its agenda. It believes community relations will be eased if immigrants integrate better. But its policies have made immigration an explosive issue.

The minister responsible, Rita Verdonk, has outlined plans to improve knowledge of the Dutch language among immigrants and to repatriate up to 26,000 failed asylum-seekers.

A speech made by Ms Verdonk after the murder of Mr van Gogh last week was described as "Hitlerian" by one immigrant group. Meanwhile, the Deputy Prime Minister, Gerrit Zalm, said the Dutch cabinet had declared war on Islamic extremists.

Even the handling of the murder inquiry has proved politically controversial as the Amsterdam chief public prosecutor, Leo de Wit, criticised the Justice minister, Piet Hein Donner, for releasing the text of the letters left with Mr van Gogh's body. One contains a direct threat to Ms Hirsi Ali and mentions two other politicians: the Liberal parliamentary leader, Jozias van Aartsen, and the Amsterdam mayor, Job Cohen.

The publication of the letters was hardly calculated to calm tensions. Mr van Aartsen later claimed that the Netherlands was in the grip of a jihad and urged increased surveillance of potential Muslim extremists.

The result is a febrile atmosphere as the country prepares forMr van Gogh's cremation today. Outside the Tariq Ziyad Ibnoe school, one young man, who calls himself Mohammed A, said: "It is not just the Muslims but the Dutch, too, who are afraid - afraid of each other."

He added: "There are extremists on the Dutch side and in the Moroccan and Muslim world. But these are a minority. The politicians and the media must stop inflaming the situation. What we need is to start talking to each other."